Hi Chris,
when I face this kind of problem I usually work like this: set the image width and height so that a blank border surrounding the image will appear showing a broken link icon:
<img src="mypic.gif" height="100px" weight="200px" alt="my pic" />
then browse to the module and right-click on the blank image, on property listing check the url, this will give you a useful tip on what's wrong.
Best regards,
Dario Rossa